Acoustic device



March 8, 1938.

H. R. CLARKE 2,110,200 ACOUSTIC DEVICE Fild Aug. 16, 1934 4 Sheets-Sheet 1 FIG.

0 VENTOR CLARKE Wm M A 7' TOR/\IE V March 8, 1938. H R, CLARKE 2,110,200

ACOUSTIC DEVICE Filed Aug. 16, 1934 4 Sheets-Sheet 2 INVENTOR h! R. CLARKE )4 TTORNEV arch 8, 1938. H, R. CLARKE 2,110,200

ACOUSTIC DEVICE Filed Aug. 16, 1934 4 Sheets-Sheet 5 FIG. 7 I

Mm 6. M

A TTORNE V Patented Mar. 8, 1938 ACOUSTIC DEVICE Harry R. Clarke, Newark, N. J., assignor to Bell Telephone Laboratories,

Incorporated, New

ork, N. Y., a corporation of New York I Application August 16, 1934, Serial No. 740,045

, 1 Claim. This invention relates to acoustic devicepand, more particularly, to telephone receivers.

An object of this invention is to simplify the structure and to facilitate the assembly of atele- 5. Ph ne re er- Another object is to improve the terminal arrangement for telephone receivers, particularly those of the unit or unitary assembly type.

A feature of this invention comprises. a frame 10 memberor casing fora receiver having a rim portion and a bridge portion of smaller dimensions than the rim so as to provide space on the rim for terminal members for the receiver energizing winding.

Another feature comprises a unitary receiver assembly including magnets held in position by clamping members provided with raised portions or bosses for engagement with, the magnets;

A further feature comprises. a unitary receiver 20 assembly including tem 'na-l clips adapted for engagement with contact studs or pins projecting from the wall of a receptacle for the assembly.

Still other and further features will be apparent from the description which follows herein- 25 after. A more complete understanding of, this inven-. tion will be. obtained from, the detailed description which follows, takenin conjunction with the appended drawings, wherein: Fig. 1 is a plan view of the receiver endof a hand telephone or handset;

Fig. 2 is a sectional view of the handset fragment shown in Fig. 1, along;the;liner2;.-2; thereof;

, Fi 3 is a b okenawayview of the handset re- 35 ceiver of 1 :and; .2, to; show details of: the ter-.

" mina ar n em n the efo a Fig. 4 is a plan viewon an enlarged scale. of the unitary receiver assembly embodied inthe device of Fig. l;

Fig- 5 is a sectional view of the device of 'Fig.v.4 along the line 4-4 thereof; i

Fig. 6 is a sectional view of the device of alongthe line Be-GL- thereof;

Fig. 7 is a plan view on an enlarged scale of 45; another unitary receiver assembly that may be embodied in the receiver. end of the handset of Fi i Fig. 8 is a sectional view of the device of Fig. 7, along the line 88'thereof 9 is a sectional view. of the device of Fig. '7, along the line 99 thereof; a r

Fig. 10 is an elevational view of a watch case type receiver, partly broken away and partly in section, embodying the receiver unit of Figs. 3-5;

Fig. 11 is a plan view of the receiver end of Fig. 4,

another hand telephone or handsetv with. the diaphragm and earpiece removed; and i Fig. 12 is a sectional View of the device of- Fig. 11, along the line l2l2 thereof.

The acoustic device of Figs; 1-6 comprises a handle or hand grip portion of molded insulating material having an enlarged, integral end portion or case 2| defining a recess 22- and having an open end defined by a rim or'annular portion 23. The rim is. provided with an annular ledge or shoulder 24 engaged by a peripheral portion of the unitary receiver assembly or receiver unit, designated generally 25. A damped diaphragm unit 26 is supported on the rim portion 2"! of the unit 215., and with the latter, is clamped within the case 2| by a receivercap or earpiece 28, provided with a plurality of spaced sound wave passages or apertures 29, and having a peripheral flange portion 30 interiorly threaded for engagement with the exteriorly threaded portion 3| of the case 2|.

The'receiver unit 25 comprises a frame, shell, casing or recessed'support 32, for instance, 'of die-cast aluminum or of molded insulating material, such as a phenol condensation product, having aperipheral annular or rim portion 21, a sub.- stantially annular, planar shelf portion 33, and a central, substantially rectangular portion 34. The portion 34 comprises a bridge portion 35, of

less diameter than the frame 32, sloping end wall members.v 35, and? vertical side wall; portions-.31. The bridge portion supports a pair of pole pieces 38, preferably of silicon steel and of substantially T-shape, the cross-bars 39 being adjacent the bridge, and the tails40 being bent to extend upwardly toward the open end 4| of the frame and substantially perpendicular to the bridge. A pair of straight, imperforate, permanent bar magnets 42, preferably of cobalt steel, are positioned on opposite sides of the pole pieces, resting on and magnetically connecting the oppositely disposed extremities of the cross-bars 39. The magnets and pole pieces are securely fastened to the bridge by a pair of clamping plates, strips or members 43 and rivets 44. The clamping members are preferably of non-magneticmaterial, suchas brass, and have a substantially U-shape, their horizontal, outwardly extending arm portions45 being provided with bosses 46 that bearagainst the upper surfaces 41 of the bar magnets. The rivets extend through aligned apertures in the bridge and pole pieces. e

The receiver energizing windingcomprises-coils 48, spaced from the horizontal portions of the pole pieces by a washer 49 of insulating material tions 40 properly spaced by locking plate 54, an. insulating washer 55 being inserted between it" and the spoolheads. This locking plate provided in accordance with the teachings of C. H.

Franks Patent 1,841,469, issued January 19, 1932;

A pair of elongated'stripsorwashers55,11, of insulating material are secured attheir ends,

for instance, by the rivets 58,- to frame portion 33 on the side of the magnet pole piece assembly having the spaced apart spoolhead lug portions. Apair of substantially U-shaped, metallic members or clips 59 having radially resilient arm portin's 50,,and the enlarged ends of the relatively thin, flexible terminal strips 5!, are clamped between .the upper strip 56 and the relatively thick lower strip 51. The strips 6! extend through the aperture 62 in the frame 32, and have-upwardly extending end portions 63 secured; as by soldering, tothe clinching bands on the'spaced apart spoolhead'lug portions. The clamped ends of stripsv SI are provided with downwarlly ex tending portio-ns 64 that fit against the arms of the clips-59. I

The receiver unit is adapted to be inserted in the case 2I: of 'the handset handle 20, to be supported on-the ledge 24, and to have-the clips- 59 engage with-the terminal studs or pins 65 projecting from'the case shoulder portion 60. The pins 65 are preferably molded in the handle, their lower [enlarged portions 61 having electrically connected thereto the conductors 68, molded in the handle inaccordance with the teachings o-f W. C. Kiesel Patent 1,425,977, issued August-15, 1922. I

Thediaphragm unit 26 comprises a pair of annular plates 69,110, of different diameters, preferably riveted. together, and enclosing acircular, planar diaphragm II and a plurality-of superposed, accordionpleated, bakelized paper, damping washers I2.v The receiver unit described hereinbeforeis compact, rugged, easily and quickly assembled, andreadily insertable and removablefrom its case. .-The"mounting of the terminal clips on the shelf portion of theframe permits. of. the provision inahandset or in a watch case receiver casing of a much shallower recess for the receiver than has been possible heretofore.

Fig. illustrates the incorporation of the hereinbefore described receiver unit in awatch case. ,t-ype receiver, designated generally. 73, the terminal studs (one only being shown) 65 being mounted in a shoulder portion 14 of the case 15. Member lGfis a stay member for a stay cord of v a conductor. p

The unitary receiver assembly or receiver unit, designated generally 80, of Figs. '7 to 9, is in many details similar to that of Figs, 1-6, like parts being like reference numerals. The'unit 80, however, comprises an annular frame member. 8 I, of. nonmagnetic; material and substantially L,-shaped in cross-section, having a pair of inwardly directed, oppositelydisposed lug portions or projections,

The magnet structure comprises a substantially C-shaped permanent magnet 83, preferably of cobalt steel, and a pair of substantially L-shaped pole pieces 84, preferably of silicon steel, the horizontal portions 85 of which are substantially trapezoidal in shape and provided with slots 86 extending inwardly from the edges. The permanent magnet and pole pieces depend from the frame 8|, and are clamped between thelugs 82 and a rectangular plate 81 of non-magnetic ma- I terial, the parts being secured by screws 88 and "clamping nuts 89. The frame member is provided with an arcuate shelf portion 90, on the under-surface of which are supported the insulating' strips '56 and 51 and the terminal clips 59, screws 9| securing the strips to the shelf.

Figs. 11 and 12 disclose the receiver end of a hand telephone or handset with the diaphragm and earpiece removed, comprising a handle 95 of insulating material having an enlarged end portion 96 having a recess 9'! defined by an interiorly threaded metallic ring 98 embedded in the handle,

The handle contains, also, conductors99 and I00,

the former terminating at a knurled insert IOI,

' disposed-centrally of the recess, and the latter at the ring 08. A receiver unit designated generally I02, is supported on the portion 90 and comprises an externally threaded metallic shell I03, for instance, of adie-cast aluminum, divided into two chambers I04 and I05 by a partition orwall'por ti0n I06.

Within the chamber I04 and supported on the upper surface I01 of the partition I 06, is a magnet structure and energizing coil assembly I08, similar in most details to that of the'receiver 'unit 25, like parts bearing like reference numerals. The clampingmembers 420, however, are provided, preferably, with'downwardly extending end portions I09 toinsure that the barmagnets remain in position on the pole pieces 38., Terminal member IIO connects one clinching band 52 and the contact spring III that contacts with the insert I0! and terminal member H2 connects the other clinching band 52 to'the magnet structure and throughthe latter to the shell I03. Member H3 is a'lock ring of insulating material.

While this invention has been disclosed with reference to several specific embodiments thereof, it is to be understood that modifications therein are possible without departing from the scope of the invention, which is to be considered as limited, therefore, by the appended claim only.

A telephone receiver unit comprising a circular frame member having a centrally disposed depending bridge portion with planar portions extending lat'erally'of the bridge portion, the frame memberhaving a peripheral flange portion, a pair of L-shaped pole pieces supported by said bridge portion, an energizing winding on each of .said pole pieces, a pair of straight bar permanent magnets supported on the horizontal portions of the pole pieces, U-shaped clamping members securedv to said bridge portion andto said polepieces and having outwardly extending portions bearing, on the ends .of vsaid magnets to force them against said pole-pieces, a pair of terminal members carriedbn the underside of one of said planar portions, and fiat flexible-strips connectingan end of each of said windings with said terminal members.

f. I HARRY R..CLARKE. 

